1. Field of the Invention
A tuned mass vibration damper such as can be used in a drivetrain of a motor vehicle, i.e., for example, within the framework of a start-up element of a motor vehicle, for damping a vibration component of a rotational movement.
2. Detailed Description of the Prior Art
In many areas of machine, plant, and automotive engineering, rotational irregularities occur when rotational movements are transmitted. These rotational irregularities can result, for example, when a rotational movement of this type is coupled into a shaft or also due to changes in the amount of energy or torque taken from the shaft and the rotational movement of the shaft.
An example is a drivetrain of motor vehicle, i.e., for example, drivetrains of passenger cars, trucks or other utility vehicles, in which an internal combustion engine is used as drive motor. Because of its principle of operation, an engine of this kind often has discontinuous torque peaks coupled into its crankshaft or into another corresponding shaft and can possibly lead to timing deviations in average torque and/or speed. Rotational irregularities of this kind can manifest themselves as vibration components of a rotational movement.
Vibration dampers are used to keep such rotational irregularities or vibration components of a rotational movement away from other components of a complex mechanical system like a drivetrain of a motor vehicle. These vibration dampers are intended to eliminate the vibration components or at least reduce the amplitude thereof. Accordingly, torsion dampers, for example, are used in a drivetrain of a motor vehicle within the framework of a start-up element. A start-up element is typically integrated between the internal combustion engine and a downstream transmission in order to allow continued running of the internal combustion engine even when the vehicle is stopped, during which the transmission input shaft is likewise stationary.
Energy accumulator elements are often employed in vibration dampers. These energy accumulator elements allow temporary absorption and, therefore, buffering of energy peaks of the rotational movement, which are then coupled into the rotational movement again at a later time. In many torsional vibration dampers, the energy accumulators which are often configured as spring elements, are connected in the actual torque path, i.e., the path of rotational movement, such that the rotational movement proceeds via the energy accumulator elements.
In contrast, in tuned mass vibration dampers no transmission of rotational movement takes place via the energy accumulator elements. The energy accumulator elements in these tuned mass vibration dampers typically comprise one or more damper masses, which can carry out oscillations in a force field to damp an unwanted vibration component of the rotational movement. The force field is formed by the forces acting on the damper masses. In particular, these forces also include a centrifugal force in addition to the weight force.
Sharply diverging requirements are sometimes imposed on corresponding tuned mass vibration dampers and the components making up the latter. Foremost in this respect, apart from functioning as efficiently as possible, are, for example, available installation space, a production in the simplest possible manner and lowest possible noise nuisance, to name only a few aspects. The components surrounding the tuned mass vibration damper typically allow only a limited installation space to be taken up by the tuned mass vibration damper in all operating states. It should also be producible in the simplest possible manner. Noise can also occur in tuned mass vibration dampers because of operation, for example, due to changes in the forces acting on the damper masses. As a result of the latter, it can happen that the damper masses of the tuned mass vibration damper are no longer guided with respect to the movement thereof substantially by centrifugal forces, but rather by the weight force acting upon them, for example, when a speed of the rotational movement and, therefore, the influence of the centrifugal forces decreases. Noises can occur when the damper masses collide with each other or with other components, for example, with the ends of their guide paths.
These noises, which are frequently metallic, can be perceived by the driver and the passengers of the motor vehicle as well as outside of the motor vehicle. These noises are frequently perceived by persons as annoying because the occurrence of these metallic noises is unexpected. For this reason, developers have tried to reduce noise generation in a tuned mass vibration damper.
DE 10 2011 087 631 A1 is directed to a low-noise torsional vibration damper comprising a centrifugal pendulum absorber with a pendulum mass carrier which is rotatable in an axial direction around an axis of rotation and two axially opposed pendulum masses which are connected to one another via a spacer. DE 10 2011 087 693 A1 is directed to a centrifugal pendulum absorber device for a damper device for a drivetrain of a motor vehicle. Provided therein at a pendulum mass carrier which is rotatable around an axis of rotation, are a plurality of pendulum masses, or pairs of pendulum masses movable in circumferential direction relative to the pendulum mass carrier. Two pendulum masses or pendulum mass pairs adjacent to one another in circumferential direction are mechanically coupled to one another via a damper element.
Apart from the most efficient possible functioning of a tuned mass vibration damper, the interest on the part of the manufacturer and developer consists in producing this tuned mass vibration damper, i.e., producing the individual components and assembling the latter to form the tuned mass vibration damper, in the simplest possible manner while simultaneously reducing noises that could be perceived as annoying by the driver and passengers of the vehicle or persons outside of the vehicle. In this regard, limitations and restrictions with respect to available installation space must often be taken into account at the same time. Therefore, there is a need to find a better compromise between a functioning of a tuned mass vibration damper, an efficient utilization of the available installation space, reduced noise during operation and the simplest possible production of this tuned mass vibration damper.